In 2011, we continued our efforts to understand the impact that phenol-soluble modulins have on biofilm development. Having shown their contribution in a recent paper using S. epidermidis as model organism (Wang et al. J Clin Invest 2011), we now analyzed the contribution this peptide family has to biofilm development of S. aureus, in particular the community-associated MRSA strain USA300. Using isogenic deletion mutants in every psm gene/operon of USA300, we could show using confocal laser scanning microscopy that all PSMs contribute to biofilm maturation processes in USA300. In animal models of catheter-related infection, we demonstrated that PSMs contribute to the dissemination of USA300 biofilm-associated infection.